I tinkered around with chainsaws back in my younger years , but to an extent. I have 4 saws and I drain the fuel mix after each season.I started to really get into the trouble shoot when two of my saws would not restart after I cut some trees down. I sold one of my saws to a guy who specializes in stihl , He told me the majority of his work is from ethnol gas and even after you drain the tanks it is still in the lines .I now use the straight mix can stuff from tractor supply. I have a poulan pro 5020 I bought 2010 ,had to mod it with a new bar and chain so it would cut like butter., So to get back ,it all boils down to the fuel mix ethnol , carb issue. I checked the spark , and gap,the mix was right , the compression was fine.so the best way that I could test was to take the plug out, put some ethnol free mix, { never use starting fluid.. always mix} in the hole with an eyedroper put the plug back in and see if I could get a burp out of it . Well she burbed , This reverts to a carb issue , granted that before hand I did replace all the fuel lines and the filter.

Look at the muffler of the newer 5020 ... it may be stamped with Husqvarna's logo. They put Husky base model engines & clutches in a lot of those after they bought the company ... I presume to jumpstart quality and the rebuilding of what had become a crappy brand reputation. Mine's 4 years old, maybe 5. Runs great and I've cut a ton of wood with it. I burn 4-6 cord a year, plus I'll use it in my landscaping business as a truck saw. It's paid for itself so many times I hate to get rid of it. Best $200 I've spent on a tool in a long time. Buy the alcohol free fuel (from the pump or pre-mixed) and your two-cycle equipment will thank you.

I generally remove the needle valves entirely and then shoot both carb cleaner and low pressure air through the valve seats to clean out any sediment or gummed up old gas. After that put the needle valves back in, gently bottom them out, and then back them off to the initial 1.5 turns setting. That generally works but Poulan is Poulan and at some point you have to know when it's a lost cause and toss it.

Exactly what I did to mine to get it to run.

I was given a 5020AV and I put in all the new parts from the kits you did and I got it to start and idle for a little bit but then it would die. I guess I need to try tuning the settings and say a Hail Mary or two and go for it! I hate adjusting the carb on anything let alone a piece of shit Poulan! It was free so I have to try it.

Never put any kind of spark plug look up the exact one that goes to that model because you will blow your saw up if you use any different kind